Governor Christie declined Monday to offer his backing to a federal lawsuit that seeks to overturn a ban on almost all betting on professional sports outside of Nevada.

Michael Drewniak, a spokesman for Christie, said that “the legal hurdles are too steep to clear. From our view, at best it’s a legal long shot.”

The suit, filed last year by state Sen. Ray Lesniak, D-Union, asks the federal court in New Jersey to overturn the 1992 Professional and Amateur Sports Protection Act. That law allowed only Nevada — and to a very limited extent, Delaware, Montana and Oregon — to offer sports betting. It also gave New Jersey 12 months to pass legislation allowing such wagering. But the deadline passed without any action by the state, so Lesniak’s hopes of allowing the struggling Atlantic City casinos to offer the additional form of gambling rests with getting the 1992 law overturned.

Christie received two extensions from the courts to give him more time to review the issue. He wrote Monday that, “given the unprecedented economic crisis and other challenges facing the state, the governor has determined that the state’s limited resources would be better utilized by focusing on other, more immediate issues.”

Lesniak and state Senate President Stephen Sweeney, D-Gloucester, who also supports the bill, said that the lawsuit would proceed without Christie’s endorsement. Sweeney said that overturning the 18-year law would amount to “undoing a past mistake.”

“I’m disappointed that the governor chose not to stand up for New Jersey’s electorate, and I’m frustrated that the governor delayed our proceedings by six months while he decided ultimately not to join in the lawsuit,” Lesniak said.

Even if Lesniak’s lawsuit were to succeed, backers of Atlantic City sports betting would still have to obtain approval of the state’s voters via a referendum. Lesniak cited an analysis that sports betting might attract $650 billion in economic activity, and generate $60 million in annual revenue to the state. Detractors claim those figures are overly optimistic.